Britain says the attacks on its diplomatic compounds in Tehran could not have taken place without a degree of consent from elements within Iran's leadership.

Protesters search an office at the British Embassy in Tehran. Staffers'… (European Pressphoto Agency )

Reporting from Tehran and Beirut — Among the protesters who sparked a diplomatic storm this week by ransacking two British diplomatic compounds in Tehran were some clutching portraits of a surprising icon, an Iranian nuclear scientist killed in a bombing one year ago.

Although it's still far from clear who exactly killed Majid Shahriari, the rioting on the first anniversary of his death highlighted anger over the Western campaign to stop Iran's nuclear program, jitters over covert steps the U.S. and its allies might be taking and divisions among Iran's leadership about how to fight back.

The tension between Iran and the West increased dramatically after the United Nations' nuclear watchdog, the International Atomic Energy Agency, issued a report Nov. 8 that cited activities it said raised the possibility of a military dimension to Iran's nuclear program.

On Wednesday, in the wake of the rampage at its diplomatic mission, the British government closed its embassy in Tehran and gave Iranian diplomats 48 hours to leave Britain. Foreign Secretary William Hague said it was "fanciful" to assume the assaults on his country's installations in Tehran could have taken place without a degree of consent from elements within Iran's leadership.

"If any country makes it impossible for us to operate on their soil, they cannot expect to have a functioning embassy here," Hague told the House of Commons, the lower house of Parliament. "This is a breach of international responsibilities of which any nation should be ashamed."

Germany and France recalled their ambassadors from Tehran for consultations. Norway closed its embassy and Italy said it was considering similar action. The U.N. Security Council, European Union, the U.S., China and other countries issued strongly worded rebukes.

Many in Iran believe that, short of a preemptive military strike, Britain, the U.S. and Israel are engaged in a campaign to destroy the Islamic Republic's nuclear program. The U.S. and Israel don't have embassies in Iran, so youths loyal to the clerical regime turned their anger on Britain, the "old fox" they accuse of doing the bidding of the "Great Satan," America.

Some of the protesters told the official Islamic Republic News Agency that they broke into the British Embassy and a residential compound to find documents to prove that Britain was behind the deaths of Shahriari and two other Iranian nuclear scientists in recent years.

Although Iran insists its nuclear program is for peaceful purposes, the U.S. and many of its allies suspect Tehran is intent on developing atomic weapons.

Last year, the Stuxnet computer worm infected equipment used in Iran's nuclear program. Many believe it was created by the U.S. or Israel.

As word of the IAEA's latest conclusions on Iran's nuclear program leaked out this fall, Israel engaged in an unusual public debate about whether to launch an attack.

Iran also has been rattled by a series of unexplained explosions.

A massive blast Nov. 12 at a missile base run by the Revolutionary Guard killed 17 people, including Maj. Gen. Hassan Moghaddam, a senior commander in the missile program. The Institute for Science and International Security, a Washington research group, released satellite images Tuesday showing the base had been largely destroyed.

Iranian officials said the blast was an accident.

But analysts say that in recent years, Iran has also been hit with a spate of explosions at refineries — and in the last year by blasts on natural gas pipelines.

On Monday, semiofficial Iranian news agencies reported an explosion in the western city of Esfahan, home to a nuclear facility. Iranian officials denied the report, and U.S. intelligence has so far detected no damage at the nuclear complex.

In Washington, former U.S. intelligence officials said an executive order that prohibits assassinations makes it extremely unlikely that the CIA would kill Iranian scientists or blow up pipelines. However, many say that Israel's Mossad spy agency might engage in such efforts to stave off what the country views as an existential threat.

The former officials say the U.S. has long engaged in sabotage to slow Iran's nuclear program, including efforts to introduce faulty spare parts.

"We definitely are doing that," said Art Keller, a former CIA case officer who worked on Iran.

Ervand Abrahamian, an Iran expert at City University of New York, said in an email that many in the Iranian leadership are convinced that Britain, the U.S. and Israel have had a hand in assassinations and sabotage.

"Although these events have received little coverage in the West, they have been front-page news in Iran," he said.

The embassy attack also revealed divisions within Iran's ruling elite about how to respond. The Foreign Ministry immediately went into damage control, expressing regret Tuesday for the actions of what it said were a small number of demonstrators.